A Zumbiel White Paper
A Comparison of Folding Carton Printing Processes Today’s packaging buyers have some viable choices in the selection of printing processes. Offset lithography, flexography, and rotogravure still dominate the industry, but additional processes such as digital, ink jet and rotary screen are also contributing to the mix.
Advancement in prepress, color management, ink brewery. Non-food applications may include personal technology, press control systems and increased care, pharmaceutical, medical, media, tobacco, hardware, speeds are benefiting each of the processes. Levels housewares, apparel, toys, sporting goods and automotive of quality as defined by resolution are ever improving, products. Each of these will impact the selection of as each of the dominant processes is now capable of printing process or processes. reproducing good quality process color images on most Design features and end use requirements such as the grades of paperboard. Enhancements such as product size and style of the package can influence the choice coding, authentication, tamper evidence, and electronic of printing process. Panels, windows, opening, closure, surveillance features serve to customize some packaging. filling line requirements, end use and end-of-life scenarios Special treatments such as metallization, holography, may favor one process over another. Some products are scuff protection, slip control, scented, dull, and glossy used indoors or outdoors. Some may be exposed to harsh surfaces can all be achieved through printing. conditions including sunlight, humidity, temperature, corrosion, bleach, oils and greases. Some may be refillable or reusable, and some may be primarily for information Printing Process Considerations purposes only. Direct food contact, taste and odor might Key Parameters Influencing play into the decision. Printing Choices Color, copy and print performance are important considerations. Photographic images still favor offset Product applications vary by category. These may include lithography, although flexography is making great inroads food products such as bakery, dry and frozen foods, ice with paperboard substrates. Metallic, opaque, white, cream novelties, candies, confectionaries, soft drinks and and fluorescent inks favor rotogravure, and overprints
www.zumbiel.com | 513.531.3600 | 2100 Gateway Blvd., Hebron, KY 41048 tend to do well with flexography. Certain colors or Primary Printing Processes sequences of inks may favor one process over another. Sheetfed Offset Lithography Print requirements may vary from one or two colors of simple text for information purposes only to nine or The most prominent process for the printing of multi- more colors of brilliant graphics for attracting attention purpose folding cartons is sheetfed offset lithography. and stimulating the senses. The print requirements It reproduces high-quality graphics with coated and for secondary packaging have traditionally been low, uncoated paperboard. Tooling costs are modest, but that’s changing with a trend toward retail-ready repeatability is good, and cartons can be printed in packaging where dual-purpose shipper units are multiple locations with similar results. ingeniously transformed into shelf-ready, point-of- Offset is a chemical form of printing, based on the purchase displays. principle that water and oil don’t mix. Images are “burned” Run length often influences the choice of printing into a light-sensitive coating on the surface of a thin process. Short to medium run lengths tend to favor offset aluminum plate. These exposed image areas are hardened lithography, longer runs may be more cost effective after processing. They are highly receptive to oily with flexo, and the longest print runs justify the high substances such as petroleum-based, soy or linseed oil tooling costs for rotogravure. Sometimes, regardless of printing inks. The unexposed non-image areas of the plate the process, higher prepress costs can be justified by remain highly receptive to water and non-receptive to ink. ganging jobs on a single press sheet, the use of extended By contacting the plate first with water and then a tacky gamut printing, and/or faster make-ready times through ink film, each of these is attracted to their respective increased automation. areas. The inked images are transferred first from the plate to a resilient rubber-covered “blanket” then pressed Sustainability is increasingly important in packaging onto the substrate. specifications. The choice of substrate has a sizeable influence on the performance of packaging against Oil-based inks and water-based dampening solutions the metrics of scorecards and life cycle assessments, are actually quite sophisticated materials, contributing including carbon footprint.1 Printing also influences these properties which are particular to the system employed. metrics. Bio-based materials for inks and adhesives are Inks are specified by curing mechanism (e.g., conventional, often preferred. VOC emissions from incineration and UV, EB and IR) as well as thickness, viscosity, tack and objectionable odors from some inks and curing systems strength of pigmentation. Dampening solutions contain are undesirable. Certain printing inks and methods additives such as “surfactants” which vastly improve the of curing can affect recyclability, compostability and efficiency by which they wet out the non-image areas on biodegradability of the package. Plate processing the plate. They also contain lubricants, anti-emulsification chemistry, solvents and cleaning materials are also agents, phosphates and/or silicates, and buffering considered. Generally speaking, aqueous-based and compounds for pH control.4 vegetable oil inks are more environmentally friendly Newer offset presses utilize water-cooled cylinders than solvent or petroleum-based inks but may result to control the buildup of heat in the ink train. Other in compromises in productivity, scratch resistance advancements such as computer-to-plate systems, 2 and gloss. automated ink fountains, scanning densitometry, Overall value can be defined as the expectation of registration control, plate mounting and blanket washing benefits gained for the price paid.3 Just as with substrates, systems, continuous feed, and delivery allow for greater low-cost inks and inconsistent print quality may be efficiency and higher repeatability. Sleeve technology acceptable for some lower margin packaging but totally allows for some presses to have a varied print length.5 unacceptable for high-end applications. Inexpensive, Offline operations include sheeting, die cutting, gluing and weaker inks and adhesives often require a thicker ink film carton assembly. Productivity is expressed as impressions to achieve acceptable results and increased energy for per hour, and today’s presses boast speeds as high as curing, thus negating any savings in cost. 16,000 iph. Primary suppliers of sheetfed offset lithographic presses include: Heidelberg, MAN Roland, KBA, Komori, Ryobi and Mitsubishi.
2 Zumbiel Packaging | A Comparison of Folding Carton Printing Processes Web Offset Lithography feed systems, laser-engraved anilox rolls, and durable plates, allowing for reduced printing pressure and Although similar to sheetfed offset, web offset improved print quality. As with web offset, productivity lithography eliminates the need for offline sheeting is measured in feet per minute, and run lengths are since rolls of paperboard are fed directly into the press. expressed in total linear feet. Typical flexo speeds are Splicing systems allow for continuous running; inline 600–800 fpm with reciprocating die cutters and up to rotary die cutting allows for carton blanks to be delivered, 1,500 fpm when printing roll-to-roll. sometimes glued and case packed sans any additional handling. Heatset, UV and EB curing systems are common Three types of flexo presses are common, including the to web offset. Productivity is measured in feet per minute, stack, inline and central impression. Primary suppliers of and run lengths are often expressed in total linear feet. flexographic presses for package printing include: Kidder, Some presses boast speeds as high as 3,000 fpm. Fischer & Krecke (F&K), Omet, Uteco, Windmoeller & Hoelscher (W&H), FMC and CMF. Web offset captures its greatest value in long runs of repeatable sizes such as national brand cereal cartons. Newspapers and magazines thrive with this process. Rotogravure Tooling costs are relatively low, and overall productivity High-quality packaging such as tobacco, brewery and is quite high. Variable sleeve presses are also gaining detergent cartons, spirits and cosmetics use rotogravure. momentum in this platform. It’s a direct application process, meaning ink is transferred directly from the plate onto the substrate. Primary suppliers of web offset lithographic presses include: Goss, Harris, Hantscho, Mitsubishi, MAN Roland As with flexo, gravure is also a mechanical form of and Müller Martini. printing; however, the image areas are represented by tiny depressions or “cells” engraved into a printing cylinder Flexography by a precision diamond stylus that is subsequently chrome plated for durability. The process of preparing the Also known as “flexo,” flexography is a fast-growing cylinders is time consuming and expensive. These costs process for package printing. It produces good quality are recovered over extremely long runs in the millions of graphics on coated and uncoated paperboard surfaces impressions. Gravure allows for printing fine detail with and flexible films. Tooling costs are slightly more than with smooth coated paperboard. Low-viscosity solvent and offset; however, advancements in inks, presses, digital water-based inks are common, and EB curing is on the plates, and sleeves are reducing make-ready times and horizon to eliminate VOC emissions and reduce energy increasing print quality. consumption.7 Lightweight sleeves are becoming available Flexography is a mechanical form of printing where a as an alternative to steel cylinders, which allow for much raised image area on a hardened photopolymer plastic easier handling and storage. plate contacts the substrate directly. Inks are highly fluidic Gravure also allows for very thick ink films, since there solvent or more commonly today, water-based solutions. is only one film split versus two with flexography and They also consist of pigments, processing aids such as many film splits with offset litho. Consequently, gravure drying accelerators or retardants, binders, and additives is capable of producing unmatched white ink opacity, as well as photo initiators in the case of UV inks.6 vivid metallics and fluorescents. The high line resolution The individual color units are much less complicated of gravure is an advantage for packages with small text.8 than with offset lithography; however, separate press Separate printing cylinders are often required to build line units are often required to build line and process colors. and process colors. Ink is transferred from a doctor blade-controlled, anilox Like flexography and web offset, rotogravure is also a metering roll to the printing plate, then directly to the web-fed process that enjoys the benefits of continuous substrate. Flexo delivers a thicker ink film than offset printing, rotary die cutting, and in some cases, inline lithography, allowing for increased opaque coverage. carton assembly. Most gravure presses are multi-color Aqueous or UV coatings are commonly applied by inline. Productivity is measured in feet per minute, and flexo alone or in combination with offset lithography. run lengths are expressed in total linear feet. Common Advancements with flexography include gearless and shaftless drive systems, sleeve technology, enclosed ink
Zumbiel Packaging | A Comparison of Folding Carton Printing Processes 3 gravure speeds are around 900 to 1,000 fpm with inline The thickest of all ink films can be delivered by screen die cutting. Roll-to-roll printing may accommodate speeds printing. In this process, the ink is pushed through a up to 1,500 fpm. fine mesh screen in selected areas which represent the Primary suppliers of gravure printing presses include: image to be printed. For package printing, this might be Chambon, Rotomec, Cerutti, Zerand, Chesnut and used to apply raised textures or an opaque white panel Bobst Champlain. as a background for full-color images. Due to a simple application process, a wider range of inks is available for use in screen printing than with any other printing Other Package Printing Processes process. Digital, ink jet and rotary screen are examples of other Combination printing captures the best of several package printing processes. These allow for variable processes. Offset presses often employ one or more images such as bar coding and custom labels to be flexo units at the back end for application of aqueous applied to any run length and are sometimes used in overprints and varnishes. Additionally, one or two flexo combination with traditional processes. Digital presses are units might be placed at the beginning of the press to lay economical for producing full-color prototypes in small down highly concentrated UV dispersion inks in spot quantities, but production runs of as much as 5,000 linear areas then building conventional offset colors on top. feet are becoming more common.9 Combination printing of offset, flexo, gravure, rotary Digital presses may include additional capabilities such screen and digital printing are all possible. as die cutting, cold-foil stamping, laminating, and two or more flexo print stations. Digital press manufacturers include: Xeikon, Canon, HP Indigo, Kodak and Xerox. Ink jet systems are often used for full-color proofing but have also been used for batch and bar coding, labels and logos. Ink jet suppliers include: AGFA, Epson, Roland, Videojet, ProteusJet, HP and KBA Metronic.
4 Zumbiel Packaging | A Comparison of Folding Carton Printing Processes It’s an exciting time for package printing, as the options abound. Finding the sweet spots in every printing opportunity is both challenging and highly rewarding. The choice of printing processes can be summarized in a decision matrix as follows:
Printing Process Decision Matrix The following are guidelines and estimates only.
Sheetfed Offset Web Offset Process Flexography Gravure Digital Lithography Lithography
Print high high very good excellent extremely high Resolution 150–175 lpi 150–175 lpi 120–150 lpi up to 300 lpi up to 1,200 dpi*
Ideal Run up to 1 million 1 million 1 million + 1.5 million + short to Length impressions impressions impressions impressions medium runs
general folding cartons, including food service, tobacco, brewery, dry and frozen high volume beverage cartons, detergent, proofing, labels, Common food, personal runs such as frozen foods, spirits, personal personalized Applications — care, medical, cereal cartons on general purpose care, for white imaging, Characteristics pharmaceutical, coated recycled folding cartons, laydown; quality continuous, drop confectionery, paperboard secondary and consistency; on demand media, on a variety packaging repeat runs of substrates
web-fed, nine nine or more web-fed unitized, or more units, six or more units, units, complex stack or common electrostatic complex ink trains web fed, ink train but impression assist, simple Presses and transfer up to 7 colors straightforward cylinder, simple inking systems, mechanisms web path inking systems combination presses
Press Cost moderate to high high wide range high moderate
photo-polymer low-cost aluminum low-cost aluminum engraved cylinders variable image Plates plastic
tacky paste consistency, oil-based, fluidic, aqueous or fluidic, aqueous or water or solvent- petro-chemical tacky paste-like Inks solvent-based solvent-based based, dry toners oil, soy or linseed consistency vegetable oil
conventional, IR, IR, UV, EB IR, UV, EB IR, UV, EB IR, UV Curing Systems UV, EB
Ink Film 1–2 microns 1–2 microns 2–3 microns up to 20 microns approx. 8 microns Thickness
offline sheeting, reciprocating or reciprocating or Sheeting, direct inline rotary some capabilities inline or offline die rotary inline die inline rotary die die cutting inline Die Cutting cutting cutting cutting
dispersion inks, sleeves, servo variable sleeve, sleeves, ceramic controls, scented, sleeves, press Techno- hybrid presses, etched cylinders, holographic, combination controls, extended press controls, laser-engraved soft touch and presses Advancements gamut extended gamut plates, extended thermographic gamut inks
*roughly equivalent to 600 lpi
Zumbiel Packaging | A Comparison of Folding Carton Printing Processes 5 Written By: About Zumbiel Dan Malenke We are Zumbiel Packaging, one of the largest privately held paperboard packaging producers in the United Dan Malenke is an accomplished training manager, with States. In our $400 billion industry, we know that your extensive coast-to-coast and international experience package is often the most important contact with your in developing and directing technical seminars for the customers; it must convey your values as well as inspire printing and packaging industries. His career includes and energize your brand. 20+ years with a Fortune 500 company, nine years of university teaching experience and accumulated work Our team of skilled and extensively trained associates in production. is dedicated to providing you with unique packaging solutions that meet your needs and budget. With more than 167 years of experience, Zumbiel stands ready to meet your packaging challenges.
For more information, please contact Zumbiel at [email protected] or 513-531-3600.
References
1) Malenke, Daniel G., “A Comparison of Folding Carton Substrates and Appropriate Applications”, Brand Packaging, April, 2010 http://www.brandpackaging.com/Articles/Case_Studies/BNP_GUID_9-5-2006_A_10000000000000805552 2) Fishman, David, “Gravure Printing Markets, Process and Inks”, All Business http://www.allbusiness.com/marketing-advertising/advertising-print-advertising/679266-1.html 3) Wikipedia http://en.wikipedia.org/wiki Value_%28marketing%29 4) Fuji Hunt Photographic Chemicals, Inc., “The Function of Fountain Solution in Lithography” http://www.fujihuntusa.com/pdfs/graphic/literature_guides/FunctionFS.pdf 5) “Sleeves in Offset Printing Offer New Freedom”, Packaging & Print Media, July, 2010 http://www.packagingprintmag.co.za/index. php?option=com_content&view=article&id=172: sleeves-in-offset-printing-offer-new-freedom&catid=65:issue-july2010&Itemid=278 6) Netzsch Premier Technologies, LLC, “Flexographic Printing Ink” http://www.netzsch-grinding.com/industries-applications/printing-inks/flexo-printing-inks.html 7) Laksin, Fontaine, Evans and Grosman, “Novel Printing Concept for Sustainable Packaging”, Package Printing, August 2010, pg. 12 http://www.mydigitalpublication.com/publication/?i=44550&p=1&utm_source CIRCULATION&utm_medium=EMAIL&utm_ campaign=20100823 8) “Gravure vs. Flexo Printing, Part 2”, Paper, Film and Foil Converter, August, 2010 http://pffc-online.com/processmanagement/gravure_versus_flexo_0809/ 9) Polischuk, Tom, “105 Years Young”, Package Printing, August 2010, pg. 10 http://www.mydigitalpublication.com/ publication/?i=44550&p=1&utm_source= CIRCULATION&utm_medium=EMAIL&utm_campaign=20100823
For more information, please contact Zumbiel at [email protected] or 513-531-3600. www.zumbiel.com | 513.531.3600 2100 Gateway Blvd., Hebron, KY 41048
281-WP-1001 | July 2012